Automotive flash MCUs at smaller nodes boost OTA reliability

Flash MCUs have reached the 28 nm process which, according to Renesas, will be instrumental in developing fuel-efficient engines as well as efficient scaling of the ECUs in the next-generation green cars and autonomous vehicles.

Flash MCUs, facilitate programmable code storage, which reduces production costs and expands the scope of real-time adaptive control applications. Not surprisingly, therefore, automotive is the single largest user of flash MCUs – and the demand for built-in flash memory is growing due to the popularity of over-the-air (OTA) functions that wirelessly and automatically update the ECU software.

[Figure 1 | Flash MCUs allow designers to select a memory area and reprogram it to modify and add features.]

Renesas, which has recently unveiled a 28 nm flash MCU, claims that it accomplishes nearly three times the performance at the same power level as compared to its 40 nm flash MCUs. The Japanese chipmaker also revealed that the Tier 1 supplier Denso has already been using this 28 nm flash MCU in its automotive designs. The new RH850/E2x Series of flash MCUs incorporate up to six 400M Hz CPU cores and 9,600 MIPS processing capabilities. The automotive control MCU, featuring built-in flash ROM of up to 16 MB, can update certain arbitrary areas during the program operation.

[Figure 2 | The block diagram of Renesas' 28nm automotive flash MCU.]

Renesas claims that a significant increase in processing power will ultimately boost MCU's control capabilities for sensor interfaces that mandate precise automotive control functions. The new flash MCU also offers improved serial interfaces, including up to 10 CAN FD channels and one Ethernet channel.

Next, security is critical in supporting safe and rapid OTA updates of ECU software. The RH850/E2x Series of flash MCUs boasts functional safety and other enhanced security functions. Targeting ASIL-D, the highest level of the ISO 26262 functional safety standard for automotive electric and electronics (E/E) systems, the new flash MCU incorporates the dual-core lock-step CPU structure, which guarantees that the calculations performed by two CPU cores are identical.

The launch of 28 nm flash MCU shows how automotive applications are driving on-chip flash to more advanced technology nodes – and the key driver behind this move is the need for more reliable performance in extreme environments.

Majeed Ahmad is the former Editor-in-Chief of EE Times Asia. He is a journalist with an engineering background and two decades of experience in writing and editing technical content. He is also the author of six books on electronics: Smartphone, Nokia’s Smartphone Problem, The Next Web of 50 Billion Devices, Mobile Commerce 2.0, Age of Mobile Data, and Essential 4G Guide.